Method for seaming wide panels of EPDM membrane to form a composite EPDM roofing membrane

ABSTRACT

A method and apparatus for continuously seaming cured EPDM membrane to form a composite sheet of predetermined width and indefinite length. The method includes the steps of providing at least two rolls of cured EPDM membrane having longitudinal marginal edges and feeding the cured EPDM membrane from the at least two rolls in a first direction. The longitudinal marginal edges of the cured EPDM membranes are positioned in an overlapping relationship as the cured EPDM membranes are fed in the first direction and then the overlapping longitudinal marginal edges are continuously seamed to form a composite sheet of indefinite length.

FIELD OF THE INVENTION

[0001] The present invention relates generally to a wide panel seamingmethod and apparatus for forming EPDM roofing membrane. Moreparticularly, the present invention relates to a method and apparatusfor continuously seaming cured stock wide panels of EPDM membrane toform a composite EPDM roofing membrane of predetermined width andindefinite length.

BACKGROUND OF THE INVENTION

[0002] EPDM is used as a single ply roofing membrane material forcovering industrial and commercial flat roofs. EPDM roofing membranehaving a thickness between {fraction (1/16)} inch and {fraction (3/32)}inch has been found to constitute an extremely useful waterproof roofingmaterial, particularly for industrial and commercial buildings havingrelatively flat roofs of very large size. Such membranes are generallyapplied to the roof surface in a vulcanized or cured state. Because ofoutstanding weathering resistance and flexibility, cured EPDM basedroofing membrane has rapidly gained acceptance. Notwithstanding the wideacceptance of EPDM based roofing membrane, a disadvantage of utilizingthese elastomers is the lack of adhesion of EPDM, especially cured EPDM,to itself. Application of cured EPDM roofing membrane is typicallyhighly labor intensive because, in applying sheets of EPDM roofingmembrane to a roof, it is usually necessary to splice cured sheets ofEPDM roofing membrane together.

[0003] Typically, the roofing material comes in rolls and is rolled onin strips running the length of the building with a slight overlapbetween adjacent strips to provide a lap joint. Unfortunately, in thepast such roofing material has typically been available only in rolls ofrelatively narrow width, for example, four feet wide. For a roof oflarge dimensions, such as 200 feet by 400 feet, the time required toapply the roofing material strips of narrow width becomes excessive and,in light of today's high labor casts, relatively expensive. To reducethe application time, and hence the cost, of roofing with EPDM sheetstock, it is desirable to provide the sheet stock in rolls of very largewidth, such as forty feet or more wide. With sheet stock of such width,a roof measuring 200 feet by 400 feet can be applied in five 40-foot by200-foot strips. The time required to roof a building in this manner isa mere fraction, of that previously necessary with sheet stock ofnarrower width, e.g., 4 feet wide. This invention relates to a methodand apparatus for providing indefinite length stock of very large widthsynthetic rubber sheeting, e.g., EPDM membrane, from indefinite lengthstock of relatively narrower width.

[0004] Accordingly, it is an object of this invention to provideindefinite length sheet stock of synthetic rubber of extremely largewidth, e.g., forty feet or more. This object has been accomplished inaccordance with certain of the principles of this invention by providingmeans to feed out in a horizontal direction from a feed roll or thelike, a plurality of rolls of stock synthetic rubber roofing, the lengthbeing equal to the length of the desired final stock and the width beingequal to the combined width of the rolls.

SUMMARY OF THE INVENTION

[0005] Briefly, according to the present invention there is provided amethod of continuously seaming cured wide panels of EPDM membrane toform a composite sheet of predetermined width and indefinite length. Themethod includes the steps of providing at least two rolls of wide panelsof cured EPDM membrane having longitudinal marginal edges and feedingthe wide panels of cured EPDM roofing membranes from the at least tworolls of stock roofing membrane in a first direction. The longitudinalmarginal edges of the wide panels of cured EPDM membranes are positionedin an overlapping relationship as the wide panels of cured EPDMmembranes are fed in the first direction and then the overlappinglongitudinal marginal edges are continuously seamed to form a compositesheet of EPDM roofing membrane of indefinite length.

[0006] The apparatus for continuously seaming wide panels of cured EPDMmembrane to form a composite roofing membrane of predetermined width andindefinite length includes at least two supply stations, a seamingstation and a storage station. The at least two supply stations supplyand simultaneously position indefinite length stock of wide panel curedEPDM membrane in an overlapping relationship. The seaming stationcontinuously seams the overlapping cured EPDM membranes to form acomposite roofing membrane of predetermined width and indefinite lengthand the storage station continuously reels the composite roofingmembrane for storage.

DESCRITPTION OF THE DRAWINGS

[0007] These and other features, advantages, and objectives of theinvention will become more readily apparent from a detailed descriptionthereof taken in conjunction with the drawings in which:

[0008]FIG. 1 is a perspective view of three rolls of overlapping curedstock wide panels of EPDM roofing membrane containing an adhesive alongthe top marginal edge;

[0009]FIG. 2 is a perspective view of three rolls of overlappingadhesive free cured stock wide panels of EPDM roofing membrane;

[0010]FIG. 3 is a perspective view of an apparatus for seaming widepanels of EPDM membrane in accordance with one aspect of the presentinvention;

[0011]FIG. 4 is an enlarged partial perspective view of a seamingstation of the apparatus of FIG. 3;

[0012]FIG. 5 is a cross-sectional view of the seaming station of theapparatus of FIG. 3 for applying adhesive between the wide panels ofEPDM membrane;

[0013]FIG. 6 is a cross-sectional view of the apparatus of FIG. 3; and

[0014]FIG. 7 is a cross-sectional view of an alternate embodiment of anapparatus for seaming wide panels of EPDM membrane in accordance withanother aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Referring to the drawings wherein like reference charactersrepresent like elements there is shown an apparatus 10 for forming acomposite roofing membrane 12 of cured EPDM membrane 14. The apparatus10 of the present invention is designed to form an indefinite lengthcomposite roofing membrane 12 of predetermined width, for example, 100feet, from an indefinite length panel of much smaller width, e.g., 10feet. A 100 foot wide roll of composite roofing membrane 12 is moreconvenient and useful in covering very large surfaces such as the roofof a large building. The time required to cover a large roof withconventional roofing membrane of relatively narrower width is many timesthat required to cover the same roof with composite roofing membraneformed in accordance with the present invention.

[0016] Referring to the figures, an apparatus 10 for forming anindefinite length composite roofing membrane 12 is shown. The apparatus10 includes at least two supply stations 16 which supply indefinitelength stock of wide panel cured EPDM membrane 14 or other similarolefin type polymers (FIGS. 3, 6 and 7). The term “EPDM” is intended tomean a terpolymer of ethylene, propylene and a diene monomer.

[0017] In one embodiment, at least one marginal edge 18 of the curedEPDM membrane 14 includes a preapplied adhesive 20 (FIG. 1). Theadhesive 20 may be a thermoplastic elastomer (TPE), thermoplasticpolyolefin (TPO) or suitable thermoplastic adhesive of a type well knownin the art. The term “thermoplastic elastomer” refers to an elastomerthat can be melt-processed (as contrasted with conventional cross-linkedrubbers). The term “thermoplastic polyolefin” refers to uncrosslinkedpolyolefins that are thermoplastic. The thermoplastic polyolefins aremade by blending ethylene-propylene polymers with polypropylene. Theethylene-propylene polymers may be blended with polypropylene byconventional mixing techniques. In an alternate embodiment,ethylene-propylene and polypropylene are made in a reactorsimultaneously creating a homogenous mixture. The polymer is formulatedwith stabilizers, pigments and antioxidants to obtain the appropriateadhesive properties. Preferred TPO's include ethylene-propylene rubberblended with polypropylene. The TPE's and TPO's can be applied usingconventional plastic techniques, such as extrusion and the like. In yetanother embodiment, the cured EPDM membrane 14 is free of adhesive (FIG.2).

[0018] The supply station 16 includes a supply roll 22 containing curedEPDM membrane 14 of indefinite length and selected width wound on ahorizontal mandrel. The mandrel is suitably journaled for rotation aboutits respective horizontal axis. The supply station 16 also includes atensioning device 24 to maintain a constant tension on the cured EPDMmembrane 14 as the membrane is fed from the supply roll 22 to a storageroll 26. In a preferred embodiment, the tensioning device 24 includes anarray of rollers suitably supported for rotation about their respectivelongitudinal axes. As shown in FIG. 3, the tensioning device 24 includesa support roll 28 that supports the cured EPDM membrane 14 as themembrane is fed from the supply roll 22 and a tensioning roll 30pivotally connected to maintain a downward pressure on the cured EPDMmembrane between the supply roll and the support roll.

[0019] The supply station 16 feeds out a selected length of cured EPDMmembrane 14 in the direction of the seaming station 32. As shown inFIGS. 1-3, the supply stations 16 are arranged in an overlapping mannerto facilitate the overlapping of cured EPDM membrane. The supplystations 16 may be arranged in an alternating overlapping arrangement(FIG. 3) or in a step-wise arrangement (FIGS. 1 and 2).

[0020] The seaming station 32, FIGS. 3-7, includes a frame member 34supporting a press assembly 36 and a device 38 for seaming theoverlapping cured EPDM membranes 14. In a preferred embodiment, thepress assembly 36 includes pinch rollers 40 and 40a suitably supportedfor rotation about their respective longitudinal axes. As theoverlapping edges of the cured EPDM membranes 14 pass between pinchrollers 40 and 40 a, the opposing pinch rollers compress the overlappingedges thereby securing the membranes together to form a seam andenhancing the permanency of the seam. It will be appreciated that theoverlapping edges of the cured EPDM membranes 14 may be compressed usingmost any suitable apparatus as well known in the art.

[0021] In one embodiment as shown in FIG. 7, the device 38 for seamingthe overlapping cured EPDM membranes 14 includes a plurality of hot airguns 42 of a type well known in the roofing membrane art. It will beappreciated that a hot air gun 42 is used to operatively seam a roofingmembrane specially manufactured to include a preapplied adhesive of thetype described above to an opposing roofing membrane. The hot air gun 42is operatively attached to the frame member 34 above the overlappingedges and directed at the overlapping edges to heat the area of overlapto weld the overlapping cured EPDM membranes together and form a seam.

[0022] In yet another embodiment as shown in FIGS. 3-6, wherein thecured EPDM roofing membrane does not contain a preapplied adhesive, thedevice 38 for seaming the overlapping cured EPDM membranes 14 includesan adhesive applicator 44 which applies adhesive to the marginal edgeregion of the upper surface of a lower wide panel of cured EPDM membraneand/or to the marginal edge region of the bottom surface of the upperwide panel of cured EPDM membrane as it is fed through the adhesiveapplicator. Any commercially available hot melt adhesive applicator 44,such as available from Norton or Pyles, can be utilized. The adhesiveapplicator 44 may terminate flow of the adhesive from the applicatorwhen the membrane is stopped to avoid undesired accumulation of adhesiveon the cured EPDM membrane. The adhesive applicator 44 also preventsadhesive 20 from being dispensed from the applicator when no cured EPDMmembrane 14 is present, whether or not the apparatus 10 is actually inoperation.

[0023] The formed composite roofing membrane 12 from the seaming station32 is then conveyed to a storage station 46 (FIGS. 6 and 7). The storagestation 46 includes a rotatable take-up roll 48 onto which the compositeroofing membrane 12 is rolled for storage purposes. Following reeling ofthe composite roofing membrane 12 on the take-up roll 48 at thestorage-station 46, the take-up roll 48 is transported for use on a roofdeck or for storage and later application to a roof deck as describedabove. The take-up roll 48 is motor-driven to convey the cured EPDMmembrane 14 from the supply roll 22 to the storage roll 28. The speedand operation of the take-up roll 48 is controlled from a control panel.

[0024] The composite roofing membrane 12 may be cut to a desired lengthby a roofing membrane cutter (not shown) of a type well known in theart. The cutter may be used to cut transversely across the fed-outcomposite roofing membrane 12 when a desired length has been fed pastthe seaming station 32 for the purpose of providing a cut sheet ofdesired length and width.

[0025] It will be appreciated that an important aspect of this inventioninheres in the fact that any number of wide panel cured EPDM membranes14 may be continuously joined together to form one large composite EPDMroofing membrane 12. Furthermore, a plurality of wider panel cured EPDMmembranes may be joined simultaneously on the apparatus 10 to formseparate larger composite EPDM roofing membranes.

[0026] The documents and patents described herein are herebyincorporated by reference.

[0027] Having described presently preferred embodiments of the presentinvention, the invention may be otherwise embodies within the scope ofthe appended claims.

What is claimed is:
 1. A method of continuously seaming wide panels ofcured EPDM membrane to form a composite roofing membrane ofpredetermined width and indefinite length comprising: providing at leasttwo rolls of wide panels of cured EPDM membrane having longitudinalmarginal edges; feeding the wide panels of cured EPDM membrane from theat least two rolls in a first direction; simultaneously positioninglongitudinal marginal edges of the cured wide panels of EPDM membrane inan overlapping relationship as the cured wide panels of EPDM membraneare fed in the first direction; and seaming the overlapping cured edgesof the EPDM membranes to form a composite roofing membrane.
 2. Themethod of claim 1 wherein the overlapping marginal edges of the widepanels of cured EPDM membrane include a preapplied adhesive therebetween.
 3. The method of claim 1 further comprising the step ofapplying an adhesive between the overlapping marginal edges of the widepanels of cured EPDM membrane.
 4. The method of claim 3 wherein theadhesive is selected from TPO or TPE.
 5. The method of claim 2 whereinthe adhesive is selected from TPO or TPE.
 6. The method of claim 2wherein the overlapping cured EPDM membranes are seamed by heating thearea of overlap to weld the overlapping cured EPDM membranes and thencompressing the area of overlap to form a seam.
 7. The method of claim 1wherein the overlapping cured EPDM membranes are seamed by applying anadhesive between the overlapping cured EPDM membranes and thencompressing the area of overlap to form a seam.
 8. The method of claim 1further comprising the step of cutting the composite roofing membrane toa desired length.
 9. An apparatus for continuously seaming wide panelsof cured EPDM membrane to form a composite roofing membrane ofpredetermined width and indefinite length comprising: at least twosupply stations for supplying and simultaneously positioning indefinitelength stock of wide panel cured EPDM membrane in an overlappingrelationship; a seaming station for continuously seaming the overlappingcured EPDM membranes to form a composite roofing membrane ofpredetermined width and indefinite length; and a storage station forcontinuously reeling the composite roofing membrane.
 10. The apparatusof claim 9 wherein the supply station includes a supply roll containingcured EPDM membrane of indefinite length and selected width and atensioning device to maintain a constant tension on the cured EPDMmembrane as the membrane is fed from the supply roll to the seamingstation.
 11. The apparatus of claim 10 wherein the tensioning deviceincludes a support roll that supports the cured EPDM membrane as themembrane is fed from the supply roll and a tensioning roll pivotallyconnected to maintain a downward pressure on the cured EPDM membranebetween the supply roll and the support roll.
 12. The apparatus of claim11 wherein the supply stations are arranged in an overlapping manner tofacilitate the overlapping of cured EPDM membrane.
 13. The apparatus ofclaim 12 wherein the supply stations are arranged in an alternatingoverlapping arrangement.
 14. The apparatus of claim 12 wherein thesupply stations are arranged in a step-wise arrangement.
 15. Theapparatus of claim 9 wherein the seaming station includes a frame membersupporting a press assembly and a device for seaming the overlappingcured EPDM membranes, the press assembly including pinch rollers tocompress the overlapping edges thereby securing the membranes togetherto form a seam.
 16. The apparatus of claim 15 wherein the seamingstation includes a plurality of hot air guns to heat the area of overlapto weld the overlapping cured EPDM membranes together and form a seam.17. The apparatus of claim 15 wherein the seaming station includes anadhesive applicator for applying adhesive between the overlapping widepanels of cured EPDM membrane.
 18. The apparatus of claim 9 wherein thestorage station includes a rotatable take-up roll onto which thecomposite roofing membrane is rolled for storage purposes.